In some motorized countries there exist the risks of encountering quite large animals, such as e.g., moose, elks, large deer and other animals of similar size, when driving along in a motor vehicle. There is of course a risk of serious consequences should a collision occur between one's own vehicle and a large animal. Collisions with such large animals often occur at significant speeds, as the animals often move quite rapidly onto the road from the cover of surrounding vegetation.
When a vehicle impacts a large animal at high speed there is a significant risk of severe injuries due to deformation of the forward parts of the vehicle roof. The vehicle roof will usually be folded downwards and pushed towards the heads of the front seat occupants if impacted by a large heavy animal when travelling at high speed. As a consequence thereof the heads of the front seat occupants will be at risk of being trapped between the intruding vehicle roof and headrests of the respective front seats of the vehicle.
A number of active safety systems for avoiding or mitigating collisions have been introduced lately. One type of system, with a potentially large positive impact on accident statistics, is a Forward Collision Avoidance System (FCAS). An FCAS uses sensors based on technologies such as RADAR (RAdio Detection And Ranging), LIDAR (LIght Detection And Ranging), LASER (Light Amplification by Stimulated Emission of Radiation) and cameras to monitor the region in front of the host vehicle. In the FCAS a tracking algorithm is used to estimate the state of the objects ahead and a decision algorithm uses the estimated states to determine any action, such as e.g., warning a driver or performing autonomous braking of the vehicle.
Automotive manufacturers are today studying collision avoidance systems providing warning and auto-braking functionality for an imminent collision with an animal. Such warning and auto-braking functionality is normally based on the use of sensors, such as those mentioned above, in order to detect the position and motion of animals. A threat assessor then estimates if the collision avoidance system equipped vehicle and the animal is on a collision course by predicting the positions a short time in the future, usually one to three seconds.
Typically, the decisions to perform warning and auto-braking are based on predictions of the paths of the host vehicle and the animal. The position and motion of the animal is, as mentioned above, determined using one or more sensors, such as camera sensors, radar sensors or laser equipment sensors, or combinations thereof.
In case predicted future paths of a host vehicle and the animal intersect within such a short time that the driver will have to act instantly in order to avoid a collision, a warning is issued. In case the predicted future paths intersect within such a short time that avoidance of a collision by either steering or braking actions performed by a driver is unlikely, auto-braking may be applied in order to avoid or mitigate the consequences of the collision.
Although the above systems provide great benefits for vehicle occupant protection in large animal collisions there is still room for improvement.